US Bridges

Iris Avenue over Wonderland Creek

Fair

Boulder County, Colorado · 0.2 MI East of 30th ST · Structure no. BOLD-54-IRIS1

Built
2020
5 years old
Condition
Fair
inspected January 2025
Type
Culvert
Concrete
Length
41 ft
2 main spans
Daily traffic
1,988
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Iris Avenue over Wonderland Creek is a concrete culvert carrying Iris Avenue over Wonderland Creek in Boulder County, Colorado. It was built in 2020, so it is 5 years old, younger than the Colorado average of 42.2 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 1,988 vehicles a day, roughly 1% of them trucks, projected to reach 2,385 by 2042. The structure is 41 ft (12.5 m) long and 84 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesIris Avenue
CrossesWonderland Creek
Location0.2 MI East of 30th ST
RouteCity Street 0
CountyBoulder County
StateColorado
Coordinates40.03656, -105.25036
Functional classUrban Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Channel and channel protection7 GoodSome minor problems.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating62.8 US tons
Inventory rating48.2 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans2
Design loadHL 93
Structure length41 ft (12.5 m)
Longest span20 ft (6 m)
Deck width84 ft (25.7 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,988 (2023)
Projected traffic2,385 by 2042
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Iris Avenue over Wonderland Creek built?

It was built in 2020, making it 5 years old in 2025.

What condition is Iris Avenue over Wonderland Creek in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in January 2025.

How much traffic does Iris Avenue over Wonderland Creek carry?

About 1,988 vehicles per day (2023 count), of which roughly 1% are trucks.

How long is Iris Avenue over Wonderland Creek?

The structure is 41 ft (12.5 m) long with a longest span of 20 ft (6 m) and a deck 84 ft wide.

Who owns Iris Avenue over Wonderland Creek?

It is owned by the City or Municipal Highway Agency.